Reversing current collector



J. N. DUNCAN REVERSING CURRENT COLLECTOR Filed July g4, 1923 Inra afa 7'.'

wir l l?. TW lia fr al l" Patented Aug. 25, 1925.

UNITED JOI-IN AN'. DUNCAN, OF BOONE, XO'WA.

REVERSING- CURRENT COLLECTOR.

Application led July 24, 1923. Serial No. 653,439.

To all whom it may concern:

Be it known that I, JOHN N. DUNCAN, a citizen of the United States of America, and resident of Boone, Boone County, iowa, have invented a new and useful Reversing Current Collector, of which the following is a. specification.

An object of this invention is to provide an improved construction for a combined trolley harp, shoe and wheel adapted for use on cars of electric railways and the like.

A further object of this invention is to provide improved means for combining and carrying a collecting shoe and wheel in an overhead trolley harp in such manner that during normal forward movement the shoe will collect current from an overhead conductor and during reverse movement, or while backing, the combined devices will .tilt so as to bring the wheel into collecting Icontact with the conductor; there being a point in the tilting movement at which the conductor is in contact with and bridges the space between the shoe and wheel.

A further object of this invention is to provide an improved construction for a current collecting shoe or sliding element in which a separate wear-resisting member is interchangeably mounted in the groove of the shoe and is adapted to sliding contact with a conductor, whereby that part of the shoe element receiving` the load of service may be renewed.

A further object of this invention is to provide an improved construction for a harp whereby the space between the stem or socket of the harp and the shoe is bridged to prevent entanglement with switches and guy wires and the like.

My invention consists in the construction, arrangement and combination of elements, hereinafter set forth, pointed out in the claims and illustrated by the accompanying drawing, in which- Figure 1 is a side elevation of my improved device in position for normal use in forward travel, dotted lines indicating positions assumed by certain of the parts when the conductor is in contact with and bridges the space between the shoe and wheel. Figure 2 is a plan of the device. Figure 3 is a central vertical longitudinal section of the device. Figure 4; is a cross-section of part of the device on the indicated line 4 4: of Figure 3.

This invention relates to, shows parts of and is an improvement on the invention described and claimed in my application for Letters Patent of the United States iiled December 26, 1922, Serial Number 608,879.

In the construction of the device as shown a harp is formed of metal by molding and consists mainly of a curved arm 10 and a socket 11 integral with each other, the arm curving out of the plane of the socket. lfthe socket 11 is adapted to receive and be carried on the upper end portion of a trolley pole of common form (not shown) and is provided witll an integral eye 12 to which a trolley-rope (not shown) may be attached for convenience in manipulation thereof. The outer end of the arm 10 is formed as an ear 13 extending transversely of and intersecting the longitudinal plane of the socket and said ear is formed with a hole in which a pin or journal 14 is mounted, said pin` projecting at both ends beyond the ends of the ear and being secured therein by a Cotter 15. Fingers 16, 17 are also formed on the outer end portion of the arm 10 on opposite sides of the base of the ear 13 and extend outwardly on parallel planes substantially tangentially of said ear. A shoe device, of substantially segmental forni is constructed of a hub 18 and spaced integral ears axially thereof, which ears lie on opposite sides of the ear 13 and are apertured for reception of and pivoting on the ends of the pin 14, said pin being passed through all of said ears before the cotter 15 is located for use. The shoe device also includes a grooved rim or peripheral portion 21, irregularly curved, integrally connected with the hub 18 by spokes 22, 23, said rim portion spanning substantially one-third a circle and outlined by intersecting arcs. The shoe device is inlaid by a wear-plate 2e located in a. recess formed in the bottom of the groove of the rim portion 21 and extending from a point near the center of said groove rearwardly around the rear end of said rim portion, the rear end of said wear plate forming a hook 25. The wear plate 24 is formed with a threaded stud 26 adapted to extend radially through a hole in the rim portion 21 and be secured by a nut 27 and cotter 28, whereby the wear plate is securely, yet removably, mounted in the rim portion. The forward end of the rim portion 21 is connected by a shunt 29, of flexible character, to the socket 11; and the shoe device has a range of vibratory movement on the arm and relative to the socket somewhat greater than is indicated by dotted lines in Figure 1, the shunt flexing and being of such length as to permit of said movement. A finger 30 is formed integral with and extends rearwardly from and at an angle to the upper portion of the soclret 11 and the extremity of said linger extends Within the groove of the rim portion Q1 and is at all times between the walls of said groove although, on account of the irregular curving of said rim, it varies in its spacing from the bottom of the groove and the wear plate in the vibration of the shoe device. It is the function of the linger 30 to bridge the space between the socket 11 and shoe device and prevent entanglement thereof with switches and guy wires of the overhead conductor system 7. Arms 31,32 are formed integrally with and extend radially of the hub 18 and are braced to the spoke 22 and bosses 33, 34 are formed on the outer ends of said arms; said arms being spaced apart and the bosses beine' apertured ier the reception of an axle A grooved trolley-wheel 36 is journaled on the axle between the arms 31, 32 and between the bosse. 33, 34 and the rim of said wheel is slightly spaced from a curved rear face of the spoke 2Q. The axle 35 is held against rotation in the bosses by a cotter 37 mounted through registering holes in the boss and one end portion of the axle. The extremities of the fingers 16, 17 are adapted to engage the lower faces of the arms 31, 32 and limit rotary movement of the shoe device in one direction. The grooved portion of the rim 21 is tapered, being wider at the rear than at the front end.

Vhen the parts arel arranged as shown by solid lines in Figures 1 and 2, the device is employed to co-llect current from the overhead conductor (represented by the horizontal dotted lilies) by sliding` contact therewith during rest or forward movement of a vehicle on which the device is carried; and when the vehicle is reversed the sliding shoe turns forwardly on the pivot of the pin 14- and brings the wheel 36 into Contact with the conductor, momentarily to bridge the space between the shoe and wheel and then turns further forwardly so as to release the shoe from the conductor and cause the wheel alone to contact therewith and -collect the current therefrom. The combined currentcollecting device is nicely balanced by means of the pin 14 so that vibration of the harp elements longitudinally of the conductor alternates the contacts of the shoe and wheel with the conductor, and, intermediate of the vibrations of the combined device, there is a point (indicated by dotted lines in Figure 1) at which both the rim portion 21 and the wheel 36 are momentarily in contact with the conductor and t-he bridging function is4 established. The sliding contact of the shoe with the conductor normally and throughout most of its use is on the wear plate 241 and said wear plate is of a material harder than the rim portion so that it will last longer and may be replaced readily, thus adding materially to the usefulness of the combined device.

I claim as my invention- 1. In a structure of the character described, a trolley harp, a shoe pivoted therein intermediate of its ends, a wear plate removably mount-ed in said shoe and adapted to sliding contact with a conductor and a hook on said wear plate extending across one end of the shoe, said wear plate being formed with a threaded stud adapted to project through a hole in the rim of said shoe, and a nut on said stud.

2. In a structure of the character described, a socket, an arm thereon, an ear on said arm, a grooved shoe having ears para-lleling said ear and pivoted thereto, fingers on said arm limiting movement of the shoe in one direction and a trolley wheel pivoted on the shoe device.

3. In a structure of the character described, a socket, an arm thereon, an ear on said arm, a grooved shoe having ears paralleling` said ear and pivoted thereto, parallel arms projecting rearwardly from the hub of said shoe, a trolley wheel pivoted between said parallel arms, and parallel fingers on the first-mentioned arm adapted to engage the lower faces of the parallel arms to limit the movement of the shoe in one direction.

Signed at Boone, in the county of Boone and State of Iowa, this 19th day of July, 1923.

JOHN N. DUNCAN. 

